IB/IPoIB: ibX: failed to create mcg debug file

commit 771a52584096c45e4565e8aabb596eece9d73d61 upstream.

When udev renames the netdev devices, ipoib debugfs entries does not
get renamed. As a result, if subsequent probe of ipoib device reuse the
name then creating a debugfs entry for the new device would fail.

Also, moved ipoib_create_debug_files and ipoib_delete_debug_files as part
of ipoib event handling in order to avoid any race condition between these.

Fixes: 1732b0ef3b3a ([IPoIB] add path record information in debugfs)
Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 42 insertions, 8 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_fs.c b/drivers/infiniband/ulp/ipoib/ipoib_fs.c
index 6bd5740e2691..09396bd7b02d 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_fs.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_fs.c
@@ -281,8 +281,11 @@ void ipoib_delete_debug_files(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
+        WARN_ONCE(!priv->mcg_dentry, "null mcg debug file\n");
+        WARN_ONCE(!priv->path_dentry, "null path debug file\n");
         debugfs_remove(priv->mcg_dentry);
         debugfs_remove(priv->path_dentry);
+        priv->mcg_dentry = priv->path_dentry = NULL;
 }
 
 int ipoib_register_debugfs(void)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 3ef7b8f049c4..08c4b0287304 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -108,6 +108,33 @@ static struct ib_client ipoib_client = {
         .get_net_dev_by_params = ipoib_get_net_dev_by_params,
 };
 
+#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
+static int ipoib_netdev_event(struct notifier_block *this,
+                              unsigned long event, void *ptr)
+{
+        struct netdev_notifier_info *ni = ptr;
+        struct net_device *dev = ni->dev;
+
+        if (dev->netdev_ops->ndo_open != ipoib_open)
+                return NOTIFY_DONE;
+
+        switch (event) {
+        case NETDEV_REGISTER:
+                ipoib_create_debug_files(dev);
+                break;
+        case NETDEV_CHANGENAME:
+                ipoib_delete_debug_files(dev);
+                ipoib_create_debug_files(dev);
+                break;
+        case NETDEV_UNREGISTER:
+                ipoib_delete_debug_files(dev);
+                break;
+        }
+
+        return NOTIFY_DONE;
+}
+#endif
+
 int ipoib_open(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
@@ -1655,8 +1682,6 @@ void ipoib_dev_cleanup(struct net_device *dev)
 
         ASSERT_RTNL();
 
-        ipoib_delete_debug_files(dev);
-
         /* Delete any child interfaces first */
         list_for_each_entry_safe(cpriv, tcpriv, &priv->child_intfs, list) {
                 /* Stop GC on child */
@@ -2074,8 +2099,6 @@ static struct net_device *ipoib_add_port(const char *format,
                 goto register_failed;
         }
 
-        ipoib_create_debug_files(priv->dev);
-
         if (ipoib_cm_add_mode_attr(priv->dev))
                 goto sysfs_failed;
         if (ipoib_add_pkey_attr(priv->dev))
@@ -2090,7 +2113,6 @@ static struct net_device *ipoib_add_port(const char *format,
         return priv->dev;
 
 sysfs_failed:
-        ipoib_delete_debug_files(priv->dev);
         unregister_netdev(priv->dev);
 
 register_failed:
@@ -2175,6 +2197,12 @@ static void ipoib_remove_one(struct ib_device *device, void *client_data)
         kfree(dev_list);
 }
 
+#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
+static struct notifier_block ipoib_netdev_notifier = {
+        .notifier_call = ipoib_netdev_event,
+};
+#endif
+
 static int __init ipoib_init_module(void)
 {
         int ret;
@@ -2227,6 +2255,9 @@ static int __init ipoib_init_module(void)
         if (ret)
                 goto err_client;
 
+#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
+        register_netdevice_notifier(&ipoib_netdev_notifier);
+#endif
         return 0;
 
 err_client:
@@ -2244,6 +2275,9 @@ err_fs:
 
 static void __exit ipoib_cleanup_module(void)
 {
+#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
+        unregister_netdevice_notifier(&ipoib_netdev_notifier);
+#endif
         ipoib_netlink_fini();
         ib_unregister_client(&ipoib_client);
         ib_sa_unregister_client(&ipoib_sa_client);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
index a2f9f29c6ab5..57eadd2b7a71 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -87,8 +87,6 @@ int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
                 goto register_failed;
         }
 
-        ipoib_create_debug_files(priv->dev);
-
         /* RTNL childs don't need proprietary sysfs entries */
         if (type == IPOIB_LEGACY_CHILD) {
                 if (ipoib_cm_add_mode_attr(priv->dev))
@@ -109,7 +107,6 @@ int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
 
 sysfs_failed:
         result = -ENOMEM;
-        ipoib_delete_debug_files(priv->dev);
         unregister_netdevice(priv->dev);
 
 register_failed: